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Old Aug 26, 2003, 11:58 AM   #1
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Default Need Canon 10d tips on taking pictures of Mars.

With all the interest in Mars at this time. I find that anytime I
try to take pictures of the moon or the cosmos, they very seldom
turn out well. I have a canon 10d and a tamron 28-300 mm
1:3.5-6.3 lens.

I bump the iso up to 600 and leave the lens open for 30 seconds
but still the pics show very little detail.

appreciate help. thanks

Bob
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Old Aug 26, 2003, 12:52 PM   #2
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... 30s is kind of slow that's why you're not getting any detail!

The camera won't be able to meter this very well, try a few shots of the moon first (since it's easier!) with a faster shutter speed starting with 1/60s... You'll see the detail and then you can gauge what to set for Mars. It's overall dark but the light is reflected from the sun so the shutter speed is up there. Bracket a few shots works best!

I have to try this myself tonight! :lol:
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Old Aug 26, 2003, 2:46 PM   #3
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are you trying to get a picture of mars's disk and features on it, like the polar caps or dark areas with a 300mm lens??? if so, you lose.
with a 300mm lens you will only get a point of light for mars. you won't see any details. if your trying to get a skyview photo with mars in it then that can work.

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Old Aug 26, 2003, 3:32 PM   #4
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mars is at 17 arcseconds in size. with a 300mm lens the image of mars on 35mm film would be apprx. 0.025 mm. if canon has a 1.6x mag over 35mm then the mars image would be approx. 0.04 mm. that's about the size of a pixel isn't it?? not very big.

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Old Aug 26, 2003, 3:53 PM   #5
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oops!!!!! sorry, 0.04mm is quite a bit bigger than 1 pixel. but, not big wnough for any detail of mars.

dennis
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Old Aug 26, 2003, 6:27 PM   #6
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Well I have no experience with space photography myself, but as it has my interest I read some tricks;
- Put camera on tripod
- In front of telescope /binoculairs
- Use remote shutter control or time delayed shutter
- Use low iso settings combined with long exposure
If that does not work crank up iso and use shorter exposure time.

Next I guess you have to use best light sensitive lense you have available, not the most zoom mm lense (as that might be 'light deaf').

Succeeded ? Share your picture, I would love to see it.
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Old Aug 26, 2003, 6:31 PM   #7
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I might try to take some pics tonight. I don't have a telescope or anything to hook my camera up to, but a c-750uz with a tcon-17 which gives me 646mm on the far end should be decent enough to see the red planet I would think. :?

Well I will give it a try tonight if I can see the thing. :P
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Old Aug 26, 2003, 6:35 PM   #8
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here's a formula for finding the linear size of an astronomical image on 35mm film. i would assume if the digcam has a multiplier then you would multiply that image size by the multiplication factor or factor it into the focal length in the calcultaions.

S = (t*Fl)/k

S = size of image in milimeters.
t = angular size of object (degrees, arcminutes, or arcseconds)
Fl = focal length of system
k = an angular constant of approx. 57.3 for degrees.

so mars is now about 17" (arcseconds) in angular size. and

S = (17*300)/57.3
S = 89.005 milimeters

ah but wait, that's if mars was at 17 degrees in size but, because it is in arcseconds we must divide by 3600 (how many secons in a degree) so the size of mars on 35 mm film would be:

89.005/3600 = 0.02472 mm or approx 0.025 mm.

multiply by an average 1.5x (digicam magnification factor) and we have an absolutely huge image on the ccd of approx. 0.04 mm.

that's how i calculateed the image size. i would think to get any detail at all you would nead at least a 1mm image which would mean you would need at least 25x the 300 mm lens or an equivalent fl of 7500 mm. maybe not that long but a lot longer than most digicams have for telephoto lenses.

dennis

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Old Aug 26, 2003, 9:10 PM   #9
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Default Thanks for help - now all I need is an unclouded sky.

binoculars - whoa! never would have thought of that one.

I was thinking of getting a 2x converter, but I suppose that
wouldn't make it much bigger.

Thanks again

Bob
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Old Aug 27, 2003, 11:15 AM   #10
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Quote:
Originally Posted by tkmckay
I might try to take some pics tonight. I don't have a telescope or anything to hook my camera up to, but a c-750uz with a tcon-17 which gives me 646mm on the far end should be decent enough to see the red planet I would think. :?

Well I will give it a try tonight if I can see the thing. :P

----
Did you manage to take any pics - Bob
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